1. Field of the Invention
One embodiment of the present invention relates to a transmitter device, a receiver device, or a broadcast system.
The present invention relates to an object, a method, or a manufacturing method. In addition, the present invention relates to a process, a machine, manufacture, or a composition of matter. One embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a semiconductor device, a display device, or a light-emitting device each including an oxide semiconductor.
In this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. In some cases, a display device, an electro-optical device, a semiconductor circuit, or an electronic device includes a semiconductor device.
2. Description of the Related Art
Increases in the resolution and the number of pixels of a display device have been demanded; for example, an 8K ultra high definition television (UHD TV) with 7680 horizontal pixels by 4320 vertical pixels has been suggested. As the number of pixels of a display device increases, the amount of display image data increases; this requires a significant increase in data transmission speed for broadcast communication.
A technique by which a transistor is formed using a semiconductor thin film formed over a substrate having an insulating surface has been attracting attention. The transistor is used in a wide range of electronic devices such as an integrated circuit (IC) or a display device. A silicon-based semiconductor is widely known as a semiconductor material that can be applied to the transistor, but an oxide semiconductor (OS) has been attracting attention as an alternative material.
For example, a technique for manufacturing a transistor using zinc oxide or an In—Ga—Zn-based oxide semiconductor as an oxide semiconductor is disclosed (see Patent Documents 1 and 2).
It is known that a transistor including an oxide semiconductor film (such a transistor is hereinafter referred to as an OS transistor) has an extremely low off-state current. Patent Document 3 discloses a technique in which a memory device is formed by using such off-state current characteristics.